I have found that I can heat up the car's interior sooner if I move the temp. selector to "cold" while the car is warming up. It takes about 5k's less driving to get the temp. guage up to normal and then of course I get lots of heat.
To help keep my windows from frosting up on the interior I lower my drivers side window about half an inch to let the moisture escape. This keeps that ultra fine frost from building up on all the interior glass.
After we get a wet snowfall be sure to clean off your car really well as the temp. usually drops soon after. I have seen peeps fighting with the frozen snow around the wiper arms and the roof the next day for nothing.